This invention relates to a thunder alarm developed for the purposes of minimizing the occurrence of lightning accidents, such as death and injury, within a limited area which accommodates a large number of visitors, audiences, players, etc., and reducing lightning troubles in a place where numerous computers and electronic gadgets are used, by means of forecasting the approach of thundercloud in proper leading time and informing their lightning activities correctly.
In recent years, automation in factories, research laboratories, and offices has developed remarkably and the number of computers and sophisticated electric gadgets has also increased. Therefore, the prevention of computer troubles caused by lightning, has become a important task.
Factories and offices using many computers urgently need proper thunder alarms that can foretell the outbreak and the approach of thunderstorms and issue an adequate warning in good time, so that operators in such factories and offices can take effective counter-measures beforehand, such as switching the computers' power line to an installed power generator or saving data into floppy disks to protect handling memories.
Therefore, reliable thunder alarms are in contemporary demand.
As to conventional methods of lightning forecast, there are a radar method, a radio wave reception method, an electric field measurement method, etc.